In the transmission of electrical signals along a conductor, it is often desirable to isolate the conductor from external sources of electromagnetic fields, to prevent interference with the signals carried by the conductor, or to prevent electromagnetic radiation from the conductor from interfering with signals carried by other conductors. Conventionally, a braided metallic shield is placed over the conductor, and spaced from it by a dielectric layer. Establishing connection to such shield braiding is, as is well-known, a somewhat difficult task, involving manual operations for preparation of the cable end. Making electrical connection to the shielding braid for establishing a grounded shield may be facilitated by the installation of a drain wire between the shield braid and the dielectric layer. Such a drain wire is usually provided where, to obtain a greater percentage of shielding efficiency, a metalized plastic film is used as the shielding member, since such film is not capable of being terminated by conventional techniques such as soldering. This technology has been applied to ribbon cables composed of miniature coaxial cables, with the drain wires disposed generally in the same planes as the central conductors of the coaxial cables, to facilitate simultaneous termination of the central conductors and individual drain wires.
However, when a shield covering an entire ribbon cable is desired, it has been necessary to place a shield braid, or a wrapping of metalized plastic film around the ribbon cable, provide a drain wire placed between the shield and the ribbon cable, and place a jacket portion over the shield braid to retain it in place. As will be apparent, this technique does not lend itself to automatic or mass termination of the conductors of the ribbon cable and the shield braid, but rather requires manual operations for termination of the shield braid.
The instant invention overcomes this and other deficiencies of the prior art.